This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The C. elegans germ line forms a syncytium, making it possible for regulatory proteins to diffuse from one cell to another. We are quantifying diffusion properties using single-point fluorescent correlation spectroscopy and pair-correlation. Those quantitative data will be used to formulate mathematical models explaining how germline stem cells make a decision to self-renew or to differentiate.